Aerosol foam skin cleanser

ABSTRACT

A packaged aerosol foaming skin cleanser can include a multiphase skin cleansing composition, a low pressure foaming agent, and a package.

FIELD OF THE INVENTION

A packaged aerosol foaming skin cleanser can include a multiphase skincleansing composition, a low pressure foaming agent, and a package.

BACKGROUND OF THE INVENTION

Foam cleansers are becoming a popular form among consumers. Foamingcleansers are often micellar with a low viscosity to allow for easyfoaming of the product. These thin, micellar compositions, while usefulfor cleansing, are not the best vehicle for delivery of benefit agentsto the skin during the cleansing process. As such, there is a need foran aerosol foam skin cleanser which has the ability to deliver benefitagents to the skin.

SUMMARY OF THE INVENTION

A packaged aerosol foaming skin cleanser, comprising: a) a multiphaseskin cleansing composition, comprising a structured surfactant phase anda benefit phase, wherein the structured surfactant phase comprises abranched structured surfactant, and the benefit phase comprises ahydrophobic benefit agent; wherein the multiphase cleansing compositionis shear thinning and has a viscosity of about 8,000 cps to about 80,000cps; b) a low pressure foaming agent; and c) a package.

This and other possible combinations will be explained in more detailbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an aerosol package;

FIG. 2A is an exploded view of the aerosol package of FIG. 1 having abag on valve configuration; and

FIG. 2B is an exploded view of the aerosol package of FIG. 1 having adip tube configuration.

DETAILED DESCRIPTION OF THE INVENTION

While the specification concludes with the claims particularly pointingand distinctly claiming the invention, it is believed that the presentinvention will be better understood from the following description.

The devices, apparatuses, methods, components, and/or compositions ofthe present invention can include, consist essentially of, or consistof, the components of the present invention as well as other ingredientsdescribed herein. As used herein, “consisting essentially of” means thatthe devices, apparatuses, methods, components, and/or compositions mayinclude additional ingredients, but only if the additional ingredientsdo not materially alter the basic and novel characteristics of theclaimed devices, apparatuses, methods, components, and/or compositions.

All percentages and ratios used herein are by weight of the totalcomposition and all measurements made are at 25° C., unless otherwisedesignated.

All measurements used herein are in metric units unless otherwisespecified.

“Foaming agent,” as used herein, refers to a material which isintermingled with a skin cleansing composition inside an aerosol packageand results in the skin cleansing composition foaming upon or shortlyafter exiting an aerosol package.

“Free of,” as used herein, means the stated ingredient has not beenadded to the aerosol foam skin cleanser, but may incidentally form as aby-product or reaction product of the other components.

“Low pressure foaming agent,” as used herein, refers to a foaming agentwith a vapor pressure of about 20 psi or less at a temperature of 21° C.which can be measured using a standard pressure gauge and method on thefoaming agent in its canister before addition to an aerosol foam skincleanser.

“Low pressure propellant,” as used herein, refers to a propellant with avapor pressure of about 20 psi or less at a temperature of 21° C. whichcan be measured using a standard pressure gauge and method on thefoaming agent in its canister before addition to an aerosol foam skincleanser.

“Multiphase,” when used with respect to skin cleansing compositions,refers to skin cleansing compositions comprising at least two chemicallydistinct phases (e.g., a structured cleansing phase and a benefitphase). Such phases can be in direct physical contact with one another.The phases of a multiphase skin cleansing composition can be blended ormixed to a significant degree, but still be physically distinct, like adispersion. In these situations, the physical distinctiveness is oftenundetectable to the naked eye. When in a blended state, the phases arestable and do not significantly phase separate while sittingundisturbed. By no significant phase separation is meant that thecomposition does not need to be shaken prior to use. In addition, in theblended configuration, the phases are not in the form of an emulsion.The phases may also be in physical contact and visually distinct.Visually distinct phases can take many forms (e.g., phases can appear asstriped, marbled). Again, visually distinct phases are stable, notphases that have separated upon standing and then need to be redispersedprior to use. The skin cleansing composition can also include acombination blended and visually distinct phases.

“Non-ionic low HLB Emulsifiers,” as used herein, refers to non-ionicsurfactants with HLB (hydrophilic and lipophilic balance) values fromabout 1.5 to about 13.

“Propellant,” as used herein, refers to a material which helps to expela skin cleansing composition from an aerosol package, but does notinteract with the skin cleansing composition until dispensing from theaerosol package.

“STnS” refers to sodium trideceth(n) sulfate, wherein n can define theaverage number of moles of ethoxylate per molecule.

“Structured” as used herein with respect to a composition or a phase,means having a rheology that confers stability on the multiphasecomposition. The degree of structure is determined by characteristicsdetermined by one or more of the following methods: the Young's ModulusMethod, Yield Stress Method, or the Zero Shear Viscosity Method, all inthe Test Methods section below. Accordingly, a surfactant phase isconsidered to be structured, if the phase has one or more of thefollowing characteristics: a Yield Stress of greater than about 0.1Pascal (Pa) to about 300 Pa; a Zero Shear Viscosity of at least about500 Pascal-seconds (Pa-s) to about 10,000 Pa-s; and/or a Young's Modulusof greater than about 1 Pascal (Pa) to about 300 Pa.

Aerosol Foam Skin Cleanser

Skin cleansers can come in many forms. A form that is gaining inpopularity is that of a foam. Foam skin cleansers may be dispensed as afoam or may foam after dispensing. Foaming skin cleansers are generallymicellar compositions which are low in viscosity which is usually lessthan 8,000 cps, which allows for easy dispensing and foaming of thecleanser. In addition, the low viscosity allows for the use ofmechanical foamers, like pump foamers, in addition to aerosol foamers.

These thin, micellar compositions, while useful for cleansing, are notthe best vehicle for delivery of benefit agents to the skin during thecleansing process. When looking to both cleanse and deliver benefitagents to the skin, structured multiphase compositions are goodcandidates, like those containing a lamellar phase. Lamellar phasecontaining compositions, however, are not seen as ideal for foaming. Thestructure of these compositions usually results in a higher viscosity,above 8,000 cps. Both the structure and the viscosity can make thesecompositions difficult to foam. In addition, since the structure helpswith the delivery of benefit agents to the skin, it is ideal to maintainthe structure of the composition even after addition of a propellant orfoaming agent.

Compositions can be structured in multiple ways. The most common way tostructure a composition is through the use of non-surfactantstructurants. These materials often consist of larger chain fatty acidsor their esters or larger chain fatty alcohols or their ethers. Thesetypes of structurants, however, form a more rigid structure which mayrequire high pressure propellant for easy dispensing from the aerosolcontainer. The high pressure propellant causes safety concerns whendistributing the aerosol products at high temperature regions.Therefore, there is a need to develop a structured surfactant which canbe dispensed with a low pressure foaming agent.

One way to overcome the negatives associated with the use ofnon-surfactant structurants is to utilize structured surfactants,especially in combination with low HLB non-ionic emulsifiers. Structuredsurfactants with low HLB non-ionic emulsifiers tend to have optimumrheology and compatibility with a low pressure foaming agent. Evenwithin the structured surfactant family, there are some materials whichare better suited for use with an aerosol foam skin cleanser. Theseinclude, for example, structured surfactants which are branched anionicsurfactants.

Another factor for consideration is the level of pressure in thepackage. Aerosol products have strict guidelines due to the pressurizednature of the material with the package and the ability of such packagesto rupture if the pressure inside the package becomes too high. This canhappen, for example, with an increase in external temperature duringtransport. The high viscosity of structured compositions would lead oneto consider the use of higher pressure propellants and/or foaming agents(vapor pressure of about 25 psi or more at 21° C.) for dispensing of theproduct to overcome the viscosity hurdle of the composition itself.However, utilizing these higher pressure propellants and/or foamingagents can be limiting from a distribution standpoint due to theconcerns of the package pressure becoming too high during transportand/or storage.

Another drawback of the use of high pressure propellants and/or foamingagents is the harshness of such high pressure on the compositionsthemselves during dispensing. The use of higher pressure propellantsand/or foaming agents can place limits on the ingredients which can beused within the formulations. High pressure propellants and/or foamingagents can also work to decrease the density of the product afterfoaming which can negatively impact the ability of the composition todeposit benefit agents to the skin. One hypothesis is that the highpressure foaming agent and/or propellant can partition into the benefitphase in the packaged product. Upon dispending the product, the foamingagent and/or propellant quickly evaporates into the gas state and mayresult in smaller particles of the benefit phase comprising the benefitagents. The smaller particles of the benefit phase comprising thebenefit agent could lead to lower deposition of the benefit agent onskin.

In addition, a high pressure foaming agent creates a low density, lowyield stress foam that has the feeling of air upon use and disappearsquickly upon lathering. A low pressure foaming agent creates aslow-releasing foam that initially looks like liquid, but when shear isapplied, quickly generates denser, higher yield stress, and more stablefoam.

One of the factors which are believed to help allow for the use of a lowpressure foaming agent and/or propellant is the rheology characteristicsof the composition. The preferred rheology for the use of a low pressurefoaming agent is as below: a Yield Stress of from about 0.1 Pascal (Pa)to about 300 Pa, from about 0.5 Pa to about 200 Pa, from about 1.0 Pa toabout 150 Pa, from about 2.0 Pa to about 100 Pa, from about 5 Pa toabout 50 Pa, or from about 10 Pa to about 50 Pa as measured by the YieldStress Method; a Zero Shear Viscosity of about 500 Pascal-seconds (Pa-s)to about 10,000 Pa-s, about 1,000 Pa-s to about 5,000 Pa-s, or about1,500 Pa-s to about 5,000 Pa-s; and/or a Young's Modulus of from about 1Pascal (Pa) to about 300 Pa, from about 5 Pa to about 200 Pa, from about10 Pa to about 150 Pa, or from about 20 Pa to about 120 Pa.

Aerosol Foam Skin Cleanser

An aerosol foam skin cleanser can include a package, a low pressurefoaming agent, and a skin cleansing composition. The package is any thatis suitable to foaming a multiphase skin cleansing composition, forexample, an aerosol package. A low pressure foaming agent includes thosefoaming agents and blends which have a vapor pressure of about 20 psi orless at 21° C. The aerosol foam skin cleanser may also comprise a lowpressure propellant. A low pressure foaming agent includes those foamingagents and blends which have a vapor pressure of about 20 psi or less at21° C. An aerosol foam skin cleanser can include from about 85 to about99, by weight of the aerosol foam skin cleanser of a skin cleansingcomposition, and from about 1% to about 15%, by weight of the aerosolfoam skin cleanser, of a low pressure foaming agent and/or low pressurepropellant.

a) Skin Cleansing Composition

A skin cleansing composition can be multiphase, for example, the skincleansing composition may include a cleansing phase and a benefit phase.The cleansing phase and the benefit phase may be in physical contact. Askin cleansing composition may include a combination of multiple phases.A skin cleansing composition may comprise from about 50% to about 99%,by weight of the composition, of a cleansing phase, and from about 1% toabout 50%, by weight of the composition, of a benefit phase. The skincleansing composition may be structured. The skin cleansing compositionmay also be shear thinning.

i) Cleansing Phase

A cleansing phase can be structured. The structure may include, forexample, a lamellar structure or phase. A cleansing phase can include aprimary surfactant. The primary surfactant can include a branchedanionic surfactant. The primary surfactant can be a structuredsurfactant. The structured surfactant can include a branched anionicsurfactant. A cleansing phase can include, for example, from about 5% toabout 30%, or from about 5% to about 25%, by weight of the skincleansing composition, of a total surfactant. A cleansing phase mayinclude, for example, from about 5% to about 30%, from about 7% to about25%, or from about 8% to about 22%, by weight of the skin cleansingcomposition, of a primary surfactant. Structured surfactants caninclude, for example, sodium trideceth(n) sulfate (STnS).

For STnS, n defines the average moles of ethoxylation. n can range fromabout 0.5 to about 2.7, from about 1.1 to about 2.5, from about 1.8 toabout 2.2, or n can be about 2. When n is less than 3, STnS can provideimproved stability, improved compatibility of benefit agents within theskin cleansing compositions, and increased mildness of the skincleansing composition.

In addition to the primary surfactant, a skin cleansing composition maycomprise a co-surfactant. A skin cleansing composition can include fromabout 1% to about 20%, by weight of the skin cleansing composition, of aco-surfactant. The co-surfactant can include, for example, anionic andzwitterionic surfactants, and non-ionic surfactants.

Examples of some suitable anionic co-surfactants include ammonium laurylsulfate, ammonium laureth sulfate, triethylamine lauryl sulfate,triethylamine laureth sulfate, triethanolamine lauryl sulfate,triethanolamine laureth sulfate, monoethanolamine lauryl sulfate,monoethanolamine laureth sulfate, diethanolamine lauryl sulfate,diethanolamine laureth sulfate, lauric monoglyceride sodium sulfate,sodium lauryl sulfate, sodium laureth sulfate, potassium laurethsulfate, sodium lauryl sarcosinate, sodium lauroyl sarcosinate, laurylsarcosine, cocoyl sarcosine, ammonium cocoyl sulfate, sodium cocoylisethionate, ammonium lauroyl sulfate, sodium cocoyl sulfate, sodiumlauroyl sulfate, potassium cocoyl sulfate, potassium lauryl sulfate,monoethanolamine cocoyl sulfate, sodium tridecyl benzene sulfonate,sodium dodecyl benzene sulfonate, and combinations thereof.

Amphoteric co-surfactants can include those that can be broadlydescribed as derivatives of aliphatic secondary and tertiary amines inwhich an aliphatic radical can be a straight or branched chain andwherein an aliphatic substituent can contain from about 8 to about 18carbon atoms such that one carbon atom can contain an anionic watersolubilizing group, e.g., carboxy, sulfonate, sulfate, phosphate, orphosphonate. Examples of compounds falling within this definition can besodium 3-dodecyl-aminopropionate, sodium 3-dodecylaminopropanesulfonate, sodium lauryl sarcosinate, N-alkyltaurines such as the oneprepared by reacting dodecylamine with sodium isethionate, N-higheralkyl aspartic acids, and combinations thereof. Other examples ofamphoteric surfactants can include sodium lauroamphoacetate, sodiumcocoamphoactetate, disodium lauroamphoacetate disodiumcocodiamphoacetate, and mixtures thereof. Amphoacetates anddiamphoacetates can also be used.

Zwitterionic co-surfactants suitable for use can include those that arebroadly described as derivatives of aliphatic quaternary ammonium,phosphonium, and sulfonium compounds, in which aliphatic radicals can bestraight or branched chains, and wherein an aliphatic substituent cancontain from about 8 to about 18 carbon atoms such that one carbon atomcan contain an anionic group, e.g., carboxy, sulfonate, sulfate,phosphate, or phosphonate. Other zwitterionic surfactants can includebetaines, including cocoamidopropyl betaine.

A cleansing phase can comprise a nonionic emulsifier. The nonionicemulsifier may be a low HLB emulsifier. A low HLB non-ionic emulsifierhas an HLB from about 1.5 to 13.0, from about 3.4 to 13.0, from about3.4 to about 9.5, or from about 3.4 to about 8.0. The skin cleansingcomposition can comprise a nonionic emulsifier at concentrations rangingfrom about 0.1% to about 10%, from about 0.25% to about 8%, from about0.5% to about 5%, from about 1.0% to about 3%, or from about 1.5% toabout 2.5%, by weight of the skin cleansing composition.

The balance between the hydrophilic and lipophilic moieties in asurfactant molecule is used as a method of classification(hydrophile-lipophile balance, HLB). The HLB values for commonly-usedsurfactants are readily available in the literature (e.g., HLB Index inMcCutcheon's Emulsifiers and Detergents, MC Publishing Co., 2004). Forexample, cocamide monoethanolamine (CMEA) is known in the art to have anHLB value of 16.8. If no value is shown in the literature, an HLB valuemay be estimated by calculation. The HLB system was originally devisedby Griffin (J. Soc. Cosmetic Chem., 1, 311, 1949). Griffin defined theHLB value of a surfactant as the mol % of the hydrophilic groups dividedby 5, where a completely hydrophilic molecule (with no non-polar groups)had an HLB value of 20.

Non-limiting examples of nonionic emulsifiers for use herein cancomprise glyceryl monohydroxystearate, isosteareth-2, trideceth-3,hydroxystearic acid, propylene glycol stearate, PEG-2 stearate, sorbitanmonostearate, glyceryl laurate, laureth-2, cocamide monoethanolamine,lauramide monoethanolamine, or mixtures thereof.

A cleansing phase may also comprise an associative polymer. Thecleansing phase can comprise from about 0.001% to about 5%, from about0.005% to about 0.5%, from about 0.007% to about 0.05%, from about0.008% to about 0.04%, or from about 0.01% to about 0.03%, by weight ofthe personal care composition, of an associative polymer.

Such associative polymers can be crosslinked, alkali swellable,associative polymers comprising acidic monomers and associative monomerswith hydrophobic end groups, whereby the associative polymer comprises apercentage hydrophobic modification and a hydrophobic side chaincomprising alkyl functional groups. Without intending to be limited bytheory, it is believed the acidic monomers can contribute to an abilityof the associative polymer to swell in water upon neutralization ofacidic groups; and associative monomers anchor the associative polymerinto structured surfactant hydrophobic domains, e.g., lamellae, toconfer structure to the surfactant phase and keep the associativepolymer from collapsing and losing effectiveness in the presence of anelectrolyte. The crosslinked, associative polymer can comprise apercentage hydrophobic modification, which is a mole percentage ofmonomers expressed as a percentage of a total number of all monomers ina polymer backbone, including both acidic and other non-acidic monomers.Percentage hydrophobic modification of the associative polymer,hereafter % HM, can be determined by the ratio of monomers added duringsynthesis or by analytical techniques such as proton nuclear magneticresonance (NMR). Associative alkyl side chains can comprise, forexample, butyl, propyl, stearyl, steareth, cetyl, lauryl, laureth,octyl, behenyl, beheneth, steareth, or other linear, branched,saturated, or unsaturated alkyl or alketh hydrocarbon side chains.

It has also been discovered that crosslinked, associative polymershaving certain % HM and certain carbon numbers of hydrophobic end groupsof alkyl side chains can provide significant enhancement of structure toskin cleansing compositions comprising a structured surfactant,especially to skin cleansing compositions comprising reduced levels ofsurfactant. Such associative polymers can also provide the abovestructure at low levels. Concentrations of associative polymers of about5% or even 10% have been known to provide a sufficient amount structure.It has been discovered that when an associative polymer % HM and analkyl side chain number of carbons can be optimized, the structure of acleansing phase can be increased using less than about 3 wt %, less thanabout 2%, less than about 1%, and less than about 0.2%, of anassociative polymer, as a weight percentage of the cleansing phase.

The acidic monomer can comprise any acid functional group, for examplesulfate, sulfonate, carboxylate, phosphonate, or phosphate or mixturesof acid groups. The acidic monomer can comprise, for example, acarboxylate. Alternatively, the acidic monomer can be an acrylate,including acrylic acid and/or methacrylic acid. The acidic monomer cancomprise a polymerizable structure, e.g., vinyl functionality. Mixturesof acidic monomers, for example acrylic acid and methacrylic acidmonomer mixtures, may be useful as well.

The associative monomer can comprise a hydrophobic end group and apolymerizable component, e.g., vinyl, which can be attached. Thehydrophobic end group can be attached to the polymerizable component,hence to the polymer chain, by different means but can be attached by anether or ester or amide functionality, such as an alkyl acrylate or avinyl alkanoate monomer. The hydrophobic end group can also be separatedfrom the chain, for example, by an alkoxy ligand such as an alkyl ether.The associative monomer can be, for example, an alkyl ester, an alkyl(meth)acrylate, where (meth)acrylate is understood to mean either methylacrylate or acrylate, or mixtures of the two.

An exemplary associative polymer can include AQUPEC® SER-300 made bySumitomo Seika of Japan, which is an acrylate/C₁₀-C₃₀ alkyl acrylatecross-polymer and comprises stearyl side chains with less than about 1%HM. Associative polymers can comprise about C₁₆ (cetyl) alkylhydrophobic side chains with about 0.7% hydrophobic modification, but apercentage hydrophobic modification can be up to an aqueous solubilitylimit in surfactant containing compositions (e.g., up to 2%, 5%, or10%). Other associative polymers can include stearyl, octyl, decyl, andlauryl side chains, alkyl acrylate polymers, polyacrylates,hydrophobically-modified polysaccharides, hydrophobically-modifiedurethanes, AQUPEC® SER-150 (acrylate/C₁₀-C₃₀ alkyl acrylatecross-polymer) comprising about C₁₈ (stearyl) side chains and about 0.4%HM, and AQUPEC® HV-701EDR which comprises about C₈ (octyl) side chainsand about 3.5% HM, and mixtures thereof. Another exemplary associativepolymer can be Stabylen 30 manufactured by 3V Sigma S.p.A., which hasbranched isodecanoate hydrophobic associative side chains.

A skin cleansing composition may also comprise a non-associativepolymer. The skin cleansing composition can comprise from about 0.01% toabout 5%, from about 0.05% to about 1%, from about 0.07% to about 0.5%,or from about 0.1% to about 0.3%, by weight of the skin cleansingcomposition, of a non-associative polymer. Suitable non-associativepolymers can include water-dispersible polymers with relatively uniformhydrophilic backbone lacking hydrophobic groups. Examples ofnon-associative polymers can include biopolymer polysaccharides (e.g.,xanthan gum, gellan gum), cellulosic polysaccharides (e.g.,carboxymethyl cellulose, carboxymethyl hydroxyethyl cellulose), otherpolysaccharides (e.g., guar gum, hydroxypropyl guar, and sodiumalginate), synthetic hydrocarbon polymers (e.g., polyacrylamide andcopolymers, polyethylene oxide, polyacrylic acid copolymers), andcombinations thereof.

A skin cleansing composition can also comprise a cationic depositionpolymer. The cationic deposition polymer can be present in an amount of0.1% to about 2%, by weight of the skin cleansing composition. Suitablecationic deposition polymers can contain cationic nitrogen-containingmoieties such as quaternary moieties. Non-limiting examples of cationicdeposition polymers can include polysaccharide polymers, such ascationic cellulose derivatives. Cationic cellulose polymers can be saltsof hydroxyethyl cellulose reacted with trimethyl ammonium substitutedepoxide, referred to in the industry (CTFA) as Polyquaternium 10, whichcan be available from Amerchol Corp. (Edison, N.J.) in their Polymer KG,JR, and LR series of polymers. Other suitable cationic depositionpolymers can include cationic guar gum derivatives, such as guarhydroxypropyltrimonium chloride, specific examples of which can includethe Jaguar® series commercially available from Rhodia Inc. and N-Hance®polymer series commercially available from Aqualon. Deposition polymerscan have a cationic charge density from about 0.8 meq/g to about 2.0meq/g or from about 1.0 meq/g to about 1.5 meq/g, or about 0.96 meq/g.

A cleansing phase may also include an electrolyte. Electrolytes may bepresent at a level of about 1% to about 10%, by weight of the skincleansing composition. Suitable electrolytes can include anions such asphosphate, chloride, sulfate, citrate, and mixtures thereof and cationssuch as sodium, ammonium, potassium, magnesium, and mixtures thereof.For example, suitable electrolytes can include sodium chloride, ammoniumchloride, sodium sulfate, ammonium sulfate, and mixtures thereof.

A cleansing phase may include water. The cleansing phase can comprisefrom about 10% to about 90%, from about 40% to about 85%, or from about60% to about 80%, by weight of the skin cleansing composition, of water.

ii) Benefit Phase

A skin cleansing composition may also comprise a benefit phase. The skincleansing compositions can include two or more benefit phases. A benefitphase can be hydrophobic and/or anhydrous. A benefit phase can also besubstantially free of or free of surfactant. A skin cleansingcomposition may include from about 3% to about 50%, by weight of theskin cleansing composition, of a benefit phase. Usually, the benefitphase is dispersed in the cleansing phase.

A benefit phase can comprise a hydrophobic benefit agent. A skincleansing composition may include from about 0.1% to about 20%, byweight of the skin cleansing composition, of a hydrophobic benefitagent. A hydrophobic benefit agent can be insoluble in the cleansingphase. Suitable benefit agents can include, for example, petrolatum,monoglyceryl monooleate, mineral oil, glycerides (e.g., soybean oil),sucrose polyesters, lanolin, lanolin derivatives, lanolin esters,lanolin oil, natural waxes, synthetic waxes, volatile organosiloxanes,derivatives of volatile organosiloxanes, non-volatile organosiloxanes,derivatives of non-volatile organosiloxanes, natural triglycerides,synthetic triglycerides, and mixtures thereof.

SEFOSE® includes one or more types of sucrose polyesters. Sucrosepolyesters are derived from a natural resource and therefore, the use ofsucrose polyesters as the benefit agent can result in a positiveenvironmental impact. Sucrose polyesters are polyester materials havingmultiple substitution positions around the sucrose backbone coupled withthe chain length, saturation, and derivation variables of the fattychains. Such sucrose polyesters can have an esterification (“IBAR”) ofgreater than about 5. For example, the sucrose polyester may have anIBAR of about 5 to about 8. In another example, the sucrose polyestermay have an IBAR of about 5-7; in another example, the sucrose polyestercan have an IBAR of about 6. In yet another example, the sucrosepolyester can have an IBAR of about 8. As sucrose polyesters can bederived from natural resources, a distribution in the IBAR and chainlength may exist. For example, a sucrose polyester having an IBAR of 6may contain a mixture of mostly IBAR of about 6, with some IBAR of about5, and some IBAR of about 7. Additionally, such sucrose polyesters mayhave a saturation or iodine value (“IV”) of about 3 to about 140. Inanother example, the sucrose polyester may have an IV of about 10 toabout 120. In yet another example, the sucrose polyester may have an IVof about 20 to 100. Further, such sucrose polyesters may have a chainlength of about C₁₂ to C₂₀.

Non-limiting examples of sucrose polyesters suitable for use includeSEFOSE® 1618S, SEFOSE® 1618U, SEFOSE® 1618H, Sefa Soyate IMF 40, SefaSoyate LP426, SEFOSE® 2275, SEFOSE® C1695, SEFOSE® C18:0 95, SEFOSE®C1495, SEFOSE® 1618H B6, SEFOSE® 1618S B6, SEFOSE® 1618U B6, SefaCottonate, SEFOSE® C1295, Sefa C895, Sefa C1095, SEFOSE® 1618S B4.5, allavailable from The Procter and Gamble Co. of Cincinnati, Ohio. Sucrosepolyesters can also be combined with other benefit agents in the benefitphase.

Non-limiting examples of glycerides suitable for use as hydrophobicbenefit agents herein can include castor oil, safflower oil, corn oil,walnut oil, peanut oil, olive oil, cod liver oil, almond oil, avocadooil, palm oil, sesame oil, soybean oil, vegetable oils, sunflower seedoil, vegetable oil derivatives, coconut oil and derivatized coconut oil,cottonseed oil and derivatized cottonseed oil, jojoba oil, cocoa butter,petrolatum, mineral oil, and combinations thereof.

Non-limiting examples of alkyl esters suitable for use as hydrophobicbenefit agents herein can include isopropyl esters of fatty acids andlong chain esters of long chain (i.e. C₁₀-C₂₄) fatty acids, e.g., cetylricinoleate, non-limiting examples of which can include isopropylpalmitate, isopropyl myristate, cetyl riconoleate, and stearylriconoleate. Other examples can include hexyl laurate, isohexyl laurate,myristyl myristate, isohexyl palmitate, decyl oleate, isodecyl oleate,hexadecyl stearate, decyl stearate, isopropyl isostearate, diisopropyladipate, diisohexyl adipate, dihexyldecyl adipate, diisopropyl sebacate,acyl isononanoate lauryl lactate, myristyl lactate, cetyl lactate, andcombinations thereof.

Non-limiting examples of alkenyl esters suitable for use as hydrophobicbenefit agents herein can include oleyl myristate, oleyl stearate, oleyloleate, and combinations thereof.

Non-limiting examples of polyglycerin fatty acid esters suitable for useas hydrophobic benefit agents herein can include decaglyceryldistearate, decaglyceryl diisostearate, decaglyceryl monomyriate,decaglyceryl monolaurate, hexaglyceryl monooleate, and combinationsthereof.

Non-limiting examples of lanolin and lanolin derivatives suitable foruse as hydrophobic benefit agents herein can include lanolin, lanolinoil, lanolin wax, lanolin alcohols, lanolin fatty acids, isopropyllanolate, acetylated lanolin, acetylated lanolin alcohols, lanolinalcohol linoleate, lanolin alcohol riconoleate, and combinationsthereof.

Non-limiting examples of silicone oils suitable for use as hydrophobicbenefit agents herein can include dimethicone copolyol,dimethylpolysiloxane, diethylpolysiloxane, mixed C₁-C₃₀ alkylpolysiloxanes, phenyl dimethicone, dimethiconol, and combinationsthereof. Still other suitable hydrophobic skin benefit agents caninclude milk triglycerides (e.g., hydroxylated milk glyceride) andpolyol fatty acid polyesters.

iii) Other Skin Cleansing Composition Materials

In addition to what has been described above, a skin cleansing may alsoinclude additional materials in any phase. These materials can includefor example, perfume, colorants, antimicrobials, pH modifiers, and thelike. Such materials are usually formulated at about 6% or less, about5% or less, about 4% or less, about 3% or less, about 2% or less, about1% or less, about 0.5% or less, about 0.25% or less, about 0.1% or less,about 0.01% or less, or about 0.005% or less by weight of the personalcare composition.

b) Low Pressure Foaming Agent

An aerosol foam skin cleanser can include a low pressure foaming agent.The low pressure foaming agent can be a hydrocarbon foaming agent. Thetotal amount of foaming agent that is part of the aerosol foam skincleanser can range from about 1% to about 20%, by weight of the aerosolfoam skin cleanser.

Suitable hydrocarbon foaming agents can include those which have a vaporpressure of about 20 psi or less at 21° C. For example, this couldinclude n-butane, an isobutane blend, isopentane, compressed gases suchas carbon dioxide, nitrous oxide, nitrogen, compressed air, or acombination thereof. n-butane has a vapor pressure of about 17 psi whenmeasured at 21° C. An isobutene blend can include, for example, acombination of isobutane and isopentane with about 25 weight percent ofthe isobutane and about 75 weight percent of the isopentane, by weightof the blend. This blend has a vapor pressure of about 7 psi at atemperature of 21° C.

The low pressure foaming agent for use in the aerosol foam skin cleansercan also be selected from the group consisting of halogenated alkenes ofgeneric formula that would include numerous HFOs and HCFOs. In addition,the foaming agent listed can be mixed with one or morehydrofluoroolefins (HFOs), hydrochlorofluoroolefins (HCFOs),hydrofluorocarbons (FFCs), chlorofluorocarbons (CFCs), hydrocarbons,alkyl ethers, and compressed gases. For example, the low pressurefoaming agent can comprise trans-1-chloro-3,3,3-trifluoropropene(Solstice® HCFO-1233zd), from Honeywell with a vapor pressure of about16.3 psi at 21° C.

c) Low Pressure Propellant

The aerosol foam skin cleanser may also comprise a low pressurepropellant. A low pressure propellant may include any of those describedabove as a low pressure foaming agent. A low pressure propellant may bepresent at a level of about 1% to about 20%, by weight of the aerosolfoam skin cleanser.

In some processes, like the bag on valve process, propellant is injectedinto the canister package during the crimping process as the drivingforce to compress a bag that is attached to the valve. This process iscalled “pressure crimping”. Pressure crimping can be accomplished usingthe technology of under-the-cup gassing. Thus, in some cases, instead ofinputting a particular amount of propellant in the package, the targetis a pressure. For low pressure applications, as discussed herein, thetarget pressure would be 20 psi or less at a temperature of 21° C. Thepackage could be filled with a propellant to a pressure of about 11 toabout 15 psi.

d) Aerosol Package

The aerosol foam skin cleanser may be included in any suitable type ofaerosol package 20, see FIG. 1. An aerosol package can include acontainer body 22 and a cap 30. An aerosol package can be, for example,in a dip tube configuration (see FIG. 2B) or a bag in bottleconfiguration, like the bag on valve configuration (see FIG. 2A).

In either the dip tube or the bag on valve configuration, the aerosolpackage 20 may have a cap 30, a valve assembly 28 attached to at least aportion of the cap 30, a valve cup 26 which may be attached to the neck24 of the container body 22 and to the valve assembly 28.

In the bag on valve configuration of FIG. 2A, a collapsible bag 32 maybe attached to the valve cup 26 and contain an aerosol foam skincleanser 42. A propellant 40, may be contained between the collapsiblebag 32 and the exterior wall 25 of the container body 22.

In the dip tube configuration of FIG. 2B, a dip tube 34 can be attachedto a valve cup 26 and reside inside the container body 22 in contactwith an aerosol foam skin cleanser 42.

e) Test Methods

a. T-Bar Viscosity Method

The viscosity of a skin cleansing composition can be assessed by theT-Bar Viscosity Method. The apparatus for T-Bar measurements includes aBrookfield DV-II+ Pro Viscometer with Helipath Accessory; a chuck,weight and closer assembly for T-bar attachment; a T-bar Spindle D, apersonal computer with Rheocalc software from Brookfield, and a cableconnecting a Brookfield Viscometer to a computer. First, weigh 80 gramsof a skin cleansing composition in a 4-oz. glass jar. Measure a T-barviscosity by carefully dropping the T-Bar Spindle to an interior bottomof the glass jar and set the Helipath stand to travel in an upwarddirection. Open the Rheocalc software and set the following dataacquisition parameters: Speed to 5 rpm, Time Wait for Torque to 00:01 (1second), and Loop Start Count to 100. Start data acquisition and turn onthe Helipath stand to travel upward at a speed of 22 mm/minute. TheT-Bar viscosity is an average T-Bar viscosity reading between the10^(th) reading and the 90^(th) reading (the first ten readings and thelast ten readings are not used for the average T-Bar viscositycalculation). The T-Bar viscosity reading is provided in cP.

b. Yield Stress, Young's Modulus, and Zero Shear Viscosity Methods

The Zero Shear Viscosity of a material which is a phase or a componentof the skin cleansing composition, can be measured either prior tocombining in the skin cleansing composition, after preparing acomposition, or first separating a phase or component from a personalcare composition by suitable physical separation means, such ascentrifugation, pipetting, cutting away mechanically, rinsing,filtering, or other separation means. The timing of the measurement candepend on what is available. For example, if a final product is all thatis available and a phase of the product is the target for measurement,then the phase will be separated prior to measurement.

A controlled stress rheometer such as a TA Instruments AR2000 Rheometeris used to determine the Yield Stress and Zero Shear Viscosity. Thedetermination is performed at 25° C. with a 4 cm diameter parallel platemeasuring system and a 1 mm gap. The geometry has a shear stress factorof 79580 m-3 to convert torque obtained to stress. Serrated plates canbe used to obtain consistent results when slip occurs.

First, the target material is positioned on a rheometer base plate; themeasurement geometry (upper plate) is moved into position 1.1 mm abovethe base plate. Excess material at the geometry edge is removed byscraping after locking the geometry. The geometry is then moved to thetarget 1 mm position above the base plate and a pause of about 2 minutesis allowed to allow loading stresses to relax. This loading procedureensures no tangential stresses are loaded at the measurement onset whichcan influence the results obtained. If the material comprises particlesdiscernible to the eye or by feel (e.g., beads) that are larger thanabout 150 microns in number average diameter, the gap setting betweenthe base plate and upper plate is increased to the smaller of 4 mm or8-fold the diameter of the 95^(th) volume percentile particle diameter.If a phase has any particle larger than 5 mm in any dimension, theparticles are removed prior to the measurement.

The measurement is performed by applying a continuous shear stress rampfrom 0.1 Pa to 1,000 Pa over a time interval of 4 minutes using alogarithmic progression, i.e., measurement points evenly spaced on alogarithmic scale. Thirty measurement points per decade of stressincrease are obtained. Stress, strain, and viscosity are recorded. Ifthe measurement result is incomplete, for example, if material isobserved to flow from the gap, results obtained are evaluated withincomplete data points excluded. If there are insufficient points toobtain an accurate measurement, the measurement is repeated withincreased number of sample points.

The Yield Stress is determined as follows. Stress (Pa) and strain(unitless) data are transformed by taking their logarithms (base 10).Log(stress) is graphed vs. log(strain) for only the data obtainedbetween a stress of 0.2 Pa and 2.0 Pa, about 30 points. If the viscosityat a stress of 1 Pa is less than 500 Pa-sec but greater than 75 Pa-sec,then log(stress) is graphed vs. log(strain) for only the data between0.2 Pa and 1.0 Pa, and the following mathematical procedure is followed.If the viscosity at a stress of 1 Pa is less than 75 Pa-sec, the zeroshear viscosity is the median of the 4 highest viscosity values (i.e.,individual points) obtained in the test, the yield stress is zero, andthe following mathematical procedure is not used. The mathematicalprocedure is as follows. A straight line least squares regression isperformed on the results using the logarithmically transformed data inthe indicated stress region, an equation being obtained of the form:Log(strain)=m*Log(stress)+b  (1)

Using the regression obtained, for each stress value (i.e., individualpoint) in the determination between 0.1 and 1,000 Pa, a predicted valueof log(strain) is obtained using the coefficients m and b obtained, andthe actual stress, using Equation (1). From the predicted log(strain), apredicted strain at each stress is obtained by taking the antilog (i.e.,10.sup.x for each x). The predicted strain is compared to the actualstrain at each measurement point to obtain a % variation at each point,using Equation (2).% variation=100*(measured strain-predicted strain)/measured strain  (2)

The Yield Stress is the first stress (Pa) at which % variation exceeds10% and subsequent (higher) stresses result in even greater variationthan 10% due to the onset of flow or deformation of the structure.

The Young's Modulus (Pa) is obtained by graphing Stress (Pa) vs. Strain(unitless) and obtaining a slope of a regression line of an initiallinear region between Stress vs. Strain, typically occurring in theregion below about 4% strain. If the relationship is not linear, thelinear regression line slope below 2% strain is taken as the Young'sModulus (Pa), using unitless strain.

The Zero Shear Viscosity is obtained by taking a first median value ofviscosity in Pascal-seconds (Pa-s) for viscosity data obtained betweenand including 0.1 Pa and a point where viscosity begins to steeplydecline. After taking the first median viscosity, all viscosity valuesgreater than 5-fold the first median value and less than 0.2× the medianvalue are excluded, and a second median viscosity value is obtained ofthe same viscosity data, excluding the indicated data points. The secondmedian viscosity so obtained is the Zero Shear Viscosity.

As set forth above, a phase or composition can be considered to bestructured if it has a Zero Shear Viscosity of about 500 Pascal-seconds(Pa-s) to about 10,000 Pa-s, a Yield Stress of greater than about 0.1Pascal (Pa) to about 300 Pa, and/or a Young's Modulus of greater thanabout 1 Pascal (Pa) to about 300 Pa.

c. Benefit Agent Deposition Method

The amount of deposition of a benefit agent can be measured in vitro.The In-Vitro deposition method measures the deposition of benefit agentson a mechanically stressed skin mimic. The method compares spectral dataof the skin mimic surface material before and after cleansing in anautomated cleansing unit.

The In-Vitro deposition method uses two 96-well microplates (hereinafterreferred to as “microplates”). Suitable 96-well microplates arecommercially available from PerkinElmer and from VWR.com. For example,the SpectraPlate 96-MG from PerkinElmer has 8 rows and 12 columns with awell volume of 400 .mu.l. The SpectraPlate 96-MG comprises theapproximate dimensions of 14.6 mm in height, 127.8 mm in length and 85.5mm in width. The SpectraPlate 96-MG has a well diameter of 7.15 mm, awell depth of 10.8 and a well to well spacing of 9.0 mm A 96-wellmicroplate is provided for containing the samples to be measured.

The in-vitro deposition method uses approximately 1536 bodies. Each bodyis approximately 2 mm in circumference spherical stainless steelbearings that comprise ferrometallic material, such as those availablefrom WLB Antriebeselemente Gmbh, Scarrastrasse 12, D-68307 Mannheim,Germany Eight bodies carefully loaded into each of the 96 wells ofmicroplates to ensure the same number is loaded into each well.

Before samples are prepared, the skin cleansing compositions areprepared according to the description in the Example Section below.After the examples of the personal care compositions are prepared,samples are prepared by combining a personal care composition anddistilled water. For each sample, 90+\−0.02 grams of distilled water isdispensed into a mixing vessel. The mixing vessel is secured to the baseof a mixer, such as a table top mixer from IKA, the mixer blades areadjusted into the distilled water within the mixing vessel. A syringe isthen zeroed on a balance. The syringe is filled with the designated skincleansing composition. The syringe is weighed and small amounts of thedesignated skin cleansing composition are dispensed until 10 grams ofthe skin cleansing composition remains in the syringe. The mixer isturned on at a speed of 500 rpm and the contents of the syringe aredispensed into distilled water within the mixing vessel. The distilledwater and the designated skin cleansing composition are mixed for 2minutes at 500 rpm forming the sample. The sample is withdrawn bysyringe from the mixing vessel while the mixer is on at a speed of 300rpm. The mixing and dispensing procedures are followed for mixing anddispensing for the control sample and the test samples 1-5. After thesamples are prepared, the control samples and test samples are dispensedin the specified wells of the microplate.

The skin mimic used in the in-vitro deposition methods is comprised of amolded bicomponent polyethylene substrate. The skin mimic is textured onone side with a pattern that resembles the texture of human skin. Thetextured side of the skin mimic is coated with 1,1,1-trimethyl-1-pentenethat is plasma deposited. The skin mimic has a total surface energy of32+/−1.0 (mJ/m²), a zeta potential of (−) 27.4 (mV), a contact angle inwater of 100° F.+/−2.0.

The preparation of the skin mimic comprises the steps of preparing themetallic mold (a), forming the substrate of the skin mimic (b) andformation of the treated test mimic of the skin mimic.

(a) Metallic Mold Preparation: A pattern resembling the texture of humanforearm skin is formed from a photograph image of human forearm skin.The pattern is transferred to a clear sheet to form a mask. A DuPont® MXseries dry film photoresists is adhered to the metal sheet. The mask isplaced on top of the metal sheet to form a metal/photoresist/mask. Thecomposite of metal/photoresist/mask is exposed to an appropriate dose ofUV light, using industry standard exposure tools. The mask is removed,the photoresist is developed and the metal sheet is etched usingappropriate etching solutions, as described in standard textbooks onsecond level microelectronics packaging, for example, Donald Seraphim,Ronald Lasky and Che-Yu Li, Principles of Electronic Packaging, Mc-GrawHill Inc. (1989).(b) Formation of the Substrate of the Skin Mimic: A 1:1 mixture ofSkin-Flex SC-89 Stretch-paint and Skin-Flex SC-89 Thinner S4 SC-89Thinner, both available from Burman Industries, (Van Nuys, Calif.) ispoured into the prepared metallic mold and allowed to dry overnight. Theamount of the mixture poured is adjusted according to the size of themold, to yield a final substrate that is typically between 600 to 800micrometers thick. After overnight drying, the substrate material iscarefully peeled off of the metallic mold.(c) Formation of the treated test region of skin mimic. The plasmadeposition is performed in a plasma unit, between the two electrodes, byapplication of the continuous wave radiofrequency (hereinafter referredto as “RF”) power. The effective plasma treatment area is approximately40 cm by 20 cm. The plasma unit comprises a cylindrical vacuum chamberhaving a diameter of approximately 30.5 cm and a length of 61.0 cm.Vacuum is produced by means of a LEYBOLD® PCS 25 vacuum pump. The RFenergy is supplied from a PE 1000 ADVANCED ENERGY®40 KHz power supply,across a set of parallel aluminum electrodes in the vacuum chamber.

The substrate is placed on a perforated aluminum sample tray in betweenparallel plate aluminum electrodes in the vacuum chamber and the vacuumchamber pressure is reduced to approximately 100 milliTorr (mTorr). Thesubstrate to be plasma coated is substantially degassed by adding amixture of argon and nitrogen gas into the vacuum chamber at flow ratesof 20 sccm of argon and 10 sccm of nitrogen, (where “sccm” meansstandard cubic centimeter per minute) for about one hour. After thesubstrate is degassed for one hour, the vacuum chamber pressure isreduced to 10 mTorr and 25 W of continuous wave RF power is applied forapproximately 5 minutes while allowing the argon/nitrogen gas mixture toflow into the vacuum chamber at flow rates of 20 sccm of argon and 10sccm of nitrogen. After 5 minutes, the release of gas is stopped andvacuum chamber is evacuated to the pressure of 10 mTorr. The1,1,1-trimethyl-1-pentene coating material available from Aldrich isintroduced into the vacuum chamber to a pressure of 100 mTorr at a flowrate selected is from about 10 sccm to 200 sccm depending the knowledgeof or may be determined with limited experimentation by one of ordinaryskill in the art. While the coating material is introduced into thevacuum chamber 25 W of continuous wave RF power is applied forapproximately 25 minutes while maintaining a vapor pressure ofapproximately 100-120 mTorr. The plasma deposition results in apolymeric coating of 1,1,1-trimethyl-1-pentene that is covalently bondedto the substrate. The exact times for plasma deposition will be withinthe knowledge or may be determined with limited experimentation by oneof skill in the art. After 25 minutes, the power to the plasma unit isturned off and the flow of the coating material is stopped. The vacuumchamber is purged with about 20 sccm argon for about 30 min prior to theremoval of the coated substrate. The plasma coated substrates areremoved from the chamber the contact angle, the surface charge and thethickness of the coating layer is determined by video contact anglemeasurement system (VCA-2500 from ASM), zeta-potential measurement(Anton Parr Electrokinetic Analyzer, Model BI-EKA) and Atomic ForceMicroscopy (Q-Scope 250 from Quesant Corporation) methods. However, oneof skill in the art will understand that a variety of coating materials,as described herein, may be used, the choice of which will be determinedby the surface property of the keratinous tissue that one desires toreproduce.

After all of the wells of the microplate are filled with the samples andthe pieces of skin are made and coated, the skin mimic is prepared forthe in vitro deposition method. Two pieces of skin mimic are prepared bycutting the skin mimic to fit on top of the openings of the wells of themicroplate while wearing gloves. The two pieces of skin mimic pieces arenumbered “1” and “2”.

A base line spectral data was obtained by the spectrophotometer for bothpieces of skin mimic. An Eye-one® IO Spectrophotometer fromGretagMacbeth with Measure Tool Software (collectively hereinafterreferred to as “spectrophotometer”) and a computer associated with thespectrophotometer (hereinafter referred to as “computer”) was utilized.The reading surface of the spectrophotometer is cleaned prior to eachreading. The reading surface of the spectrophotometer is black in orderto provide adequate reflection. The first piece of skin mimic is placedon the reading surface with the textured and treated region of the skinmimic facing the spectrophotometer. Next, a piece of plastic having aplurality of holes which correspond in size to the openings of themicroplate is placed over the textured and treated region of the skinmimic A scan is then performed using the robot arm of thespectrophotometer. The baseline spectral data for the first piece ofskin mimic is saved on a computer as the first baseline. The readingsurface of the spectrophotometer is cleaned and the spectral data forthe second piece of skin mimic surface is, as described for the firstpiece of skin mimic. The baseline spectral data for the second piece ofskin mimic is saved on the computer as the second baseline.

Next, the pieces of skin mimics are arranged over the openings of thewells of the microplates. The pieces of skin mimic surface material aretransferred to cover the openings of the wells of the each of themicroplates to ensure that the textured and treated region of the skinmimic is facing the openings of the wells of the microplate. A lid isplaced over each piece of the skin mimic and the associated microplateto form a lidded microplate.

The next step is to place the lidded microplates into the microplateholders 20 of automated cleansing unit. The automated cleansing unitcomprises a horizontal base comprising four microplate holders. Thehorizontal base is made of rectangle of aluminum comprising thefollowing approximate dimensions of ⅜ inch in height, fourteen inches inwidth and twenty seven inches in length. The automated cleansing unitcomprises two vertical supports comprised of aluminum with theapproximate dimensions of one inch by two inches by ten and ¾ of an inchin height. The vertical supports are attached to a horizontal supportcomprising a rodless air slide. The horizontal support comprising arodless air slide comprises the approximately dimension of a ½ inch bytwo inches by twenty six and ½ inches in height. Suitable rodless airslides comprise a one inch bore and eleven inch stroke and haveassociated end lugs and mount brackets, which are commercially availablefrom McMaster-Carr. The rodless air slide is double acting and comprisesa carriage that is connected to an internal piston and two compressedair ports.

The automated cleansing unit comprises two magnetic arms. The horizontalsupport comprising a rodless air slide is the structure upon which thetwo magnetic arms are mounted. The magnetic arms are mounted to therodless air slide such that the magnetic arms move back and forth alongthe length of the double acting rodless air slide by the force ofcompressed air. Each of the magnetic arms are comprised of aluminum andhave the approximate dimensions of one inch by two inches by fourteeninches in length and have a “T” shape channel that houses sevenneodymium iron boron magnets (not shown). Each of the neodymium ironboron magnets has the approximate dimensions of two inches in length,one inch in width and half or an inch in height. Each of the neodymiumiron boron magnets comprises a magnetic strength of 12200 Gauss,available from Edmund Scientifics. The magnetic arms are configured at aheight of about 2.75 cm above the microplate holder with the caveat thatthe magnets maintain their function to attract and move the bodiescomprised within the wells of the microplate. The magnetic arms moveback and forth along the length of the rodless air slide by the force ofcompressed air at a speed of approximately 6 back and forth sweeps overthe length of the rodless air slide over a 10 second time period.

Below the magnetic arms are configured four microplate holders. Each ofthe microplate holders comprise a clamping plate and four pistonsattached to a pneumatic control unit. When actuated, the pistons for thepneumatic control unit hold the microplates in the four microplateholders at a pressure of from about 90 psi. Prior to placing the liddedmicroplates into the microplate holders of automated cleansing unit, thepneumatic control unit is turned on.

Components of the pneumatic control unit are connected to the rodlessair slide, the piston and clamping plates. The pneumatic control unit isused to apply compressed air to the automated cleansing unit, whichimparts a force by converting the potential energy of compressed airinto kinetic energy. The pneumatic control unit comprises a solenoid aircontrol valve, a distribution manifold outlet, a compressed air controlvalve, a compressed air flow regulator, an alternating output binaryvalve, a two-hand safety pneumatic control valve, a compressed aircontrol valve and various connectors that provide pressurized air to theautomated cleansing unit from an external air source. The air controlvalve, air flow regulators, alternating a binary valves, a two-handsafety pneumatic control valve are positioned upstream of a solenoid aircontrol valve. A suitable solenoid air control valve, in one embodiment,is described as a double air style valve with a 10 psi to 120 operatingpressure. Suitable compressed air flow regulators can operate in thepressure range of 14 psi to 116 psi. Suitable air control valvealternating output binary valves operate in a 35 psi to 100 psi range.All of the components of the pneumatic control unit are available fromMcMaster-Carr®.

The microplate holder is designed to hold four commercially available 96well microplates. The microplate holder comprises a riser, an aluminumbase plate, a clamping plate and pistons. Riser has a larger dimensionthan the approximately dimension of a commercially available microplate.In some embodiments, the riser has the dimensions five inches by fiveand ¾ inches. The riser is comprised of polyoxymethylene which iscommonly known under DuPont's brand name DELRIN®® is used as a metalsubstitute because it is a lightweight, low-friction, and wear-resistantthermoplastic that possesses good physical and processing properties andcapable of operating in temperatures in excess of 90° C. In addition tothe riser, the microplate holder, in some embodiments, comprises analuminum base plate. The aluminum base plate has a raised portion and atrench which is approximately the same dimensions as a commerciallyavailable microplate, such that the bottom of the wells rest on theraised portion and the perimeter of the microplate fit in the trench.The aluminum base plate is designed such that the microplate is notadversely affected by the compression of the clamping plate by thepiston when the pneumatic pressure unit is actuated.

The aluminum base plate comprises a first heater and the clamping platecomprises a second heater. The first heater and second heater compriseflexible silicone rubber heaters available from Omega.com. The firstheater and the second heater can be controlled by a ¼ DIN six zonetemperature controller with RS-232 communications and free configurationsoftware available by from Omega.com. The first heater and the secondheater are used to stabilize the temperature of the sample and the skinmimic at room temperature ranging from about 20° C. to about 25° C.Prior to placing the lidded microplates into the microplate holders ofautomated cleansing unit, the first heater and the second heater areturned on to stabilize the temperature of the sample and the skin mimicat room temperature ranging from about 20° C. to about 25° C.

The lidded microplates are placed into the microplate holders andpneumatic control unit is actuated such that the lidded microplates areheld under 90 psi of pressure. The magnetic arms are actuated on andarms moves over the lidded microplates at a height of 2.65 cm above themicroplate holders. The magnetic arms of the automated cleansing unit,sweep back and forth over the microplate holders for 5 minutes, at aspeed of 6 sweeps per every 10 seconds. After 5 minutes of the automatedcleansing process, the lidded microplates are removed from themicroplate holders and are disassembled so that spectral data isgathered by a spectrophotometer for both pieces of skin mimic surfacematerial.

Prior to the spectral readings, two large 4000 ml beakers of 20° C. to25° C. water are filled. The first piece of skin mimic is removed fromthe first microplate and submerged in the tap water within the firstbeaker five times. The second piece of skin mimic is removed from thesecond microplate and submerged within the second beaker five times. Thecompleteness of rinsing step is judged visually by the lack of foam onthe skin mimic and presence of defined circles of deposited material onthe skin mimic. Both piece of skin mimic are blotted with paper towelsand fumed in a drying hood for five minutes each. The reading surface ofthe spectrophotometer is cleaned. The first piece of skin mimic isplaced on the reading surface with the textured and treated region ofthe first skin mimic facing the spectrophotometer. Next, a piece ofplastic having a plurality of holes which correspond in size to theopenings of the microplate is placed over the textured and treatedregion of the first skin mimic. The scan is then performed using therobot arm of the spectrophotometer. The baseline spectral data for thefirst piece of skin mimic material is saved for comparison with thefirst baseline. The reading surface of the spectrophotometer is cleanedand the spectral data for the second piece of skin mimic surfacematerial is obtained by the aforesaid method. The baseline spectral datafor the second skin mimic surface material is saved on a computer forcomparison with the second baseline.

The spectrophotometer measures the L-a-b values for the skin mimicsurface material before cleansing and after washing. The depositionvalues of the in-vitro method are reported as a Delta L value and areindicative of the deposition profile of each sample. The difference ofthe light intensity L or “Delta-L” is the L value after the cleansing-Lvalue before cleansing (the baseline spectral data).

The Deposition Method is also available in U.S. Patent Application Pub.No. 20100158830.

EXAMPLES

Inventive Example 1 is a skin cleansing composition which can beincluded as part of an aerosol foam skin cleanser.

Inventive Example 1 Branched sodium trideceth-2-sulfate ST2S  9.21%Cocamidopropyl betaine  2.75% Trideceth-3 Iconal TDA-3-EthoxylatedTridecyl  1.31% Alcohol Sodium Chloride  4.02% Guar, HydroxypropylTrimonium Chloride, N-  0.34% Hance CG-17 Acrylates/C10-30 AlkylAcrylates Cross 0.027% Polymer PEG-90M  0.12% Xanthan gum  0.26%Petrolatum   10% Soybean Oil  4.85% Monoglyceryl Monooleate  0.1%Butylated hydroxyltoluene (BHT) 0.098% Disodium EDTA  0.13% SodiumBenzoate  0.27% Preservative 0.033% Perfume  0.25% Water Q.S pH (using,citric acid to adjust) 5.7

Inventive Example 1 is a blended multiphase composition, wherein thebenefit phase (including petrolatum, soybean oil, butylatedhydroxyltoluene, and monoglyceryl monooleate) is dispersed in acleansing phase. This composition is made by adding water to a mainmixing vessel. Sodium chloride, xanthan gum, guar hydroxypropyltrimoniumchloride, and sodium trideceth sulfate are added to the water withconstant mixing. While that is mixing, a polymer premix is prepared bycombining Acrylates/C10-30 Alkyl Acrylates and PEG-90M into trideceth-3with mixing. Once the polymer premix is dispersed, the premix is addedto the main mixing vessel. Cocamidopropyl betaine, EDTA, and sodiumbenzoate are then sequentially added to the main mixing vessel withmixing. The pH is then adjusted to about 5.7 with the addition of a pHmodifier (like citric acid). Preservative and perfume are then addedwith mixing.

The benefit phase is prepared by first creating a lipid premix byheating soybean oil to about 50° C. in a separate vessel. Monoglycerylmonooleate and butylated hydroxyltoluene are added to the soybean oilwith mixing. The lipid premix is then added to the main vessel withstirring. In a separate vessel, petrolatum is heated to about 88° C.with mixing. The petrolatum is then cooled to about 60° C. and added tothe main mixing vessel with mixing. The composition is mixed untilhomogenous.

Inventive Examples 2-7 are of aerosol foam skin cleansers including askin cleansing composition (Inventive Example 1), a low pressure foamingagent, and a package.

Inventive Inventive Inventive Inventive Inventive Inventive Example 2Example 3 Example 4 Example 5 Example 6 Example 7 Inventive Example 197% 95% 92% 97% 95% 92% Foaming agent (25  3%  5%  8% — — — wt %isobutane & 75 wt % isopentane) Foaming agent (n- — — —  3%  5%  8%butane) Packaging Bag On Bag On Bag On Bag On Bag On Bag On valve valvevalve valve valve valve Propellant - Yes Yes Yes Yes Yes Yes compressedair filled to 12-15 psi Foam Density (g/ml) 0.4 0.26 0.15 0.27 0.10 0.06Foam Rheology - 61 32 6 15 10 7.6 Young's Modulus (Pa) Foam Rheology1571 694 201 444 325 298 Zero Sheer Viscosity (Pa · S) Petrolatum 803430 532 558 363 284 Deposition (μg/cm²) Soy bean oil 60 49 60 47 38 49Deposition (μg/cm²)

Inventive Examples 2-7 are made by first premixing the skin cleansingcomposition with foaming agent in a closed system and then injecting themixture into a bag which is fastened to a valve through the standardcrimping process. Then, the valve with bag and mixture is crimped onto acan (either metal, plastic, or glass). Then, propellant is added intothe can, but outside of the bag to provide a positive pressuredifferential outside of the bag.

Inventive Example 8 is a skin cleansing composition which can beincluded as part of an aerosol foam skin cleanser.

Inventive Example 8 Branched sodium trideceth-2-sulfate ST2S   23%Cocamidopropyl betaine    7% Trideceth-3 Iconal TDA-3-EthoxylatedTridecyl  1.86% Alcohol Sodium Chloride  4.75% Guar, HydroxypropylTrimonium Chloride, N-  0.4% Hance CG-17 Soybean Oil  4.85% MonoglycerylMonooleate  0.05% Butylated hydroxyltoluene (BHT) 0.098% Disodium EDTA 0.13% Sodium Benzoate  0.27% Preservative 0.033% Perfume  0.25% WaterQ.S pH (using citric acid to adjust) 5.7

Inventive Example 8 is a blended multiphase composition, wherein thebenefit phase (including soybean oil, butylated hydroxyltoluene, andmonoglyceryl monooleate) is dispersed in the cleansing phase. Thiscomposition is made by adding water to a main mixing vessel. Sodiumchloride, guar hydroxypropyltrimonium chloride, sodium tridecethsulfate, and cocamidopropyl betaine are added to the water with constantmixing. Then add EDTA and sodium benzoate. The pH is then adjusted toabout 5.7 with the addition of a pH modifier (like citric acid). Thenadd the preservative and perfume with good mixing.

The benefit phase is prepared by first creating a lipid premix byheating soybean oil to about 50° C. in a separate vessel. Monoglycerylmonooleate and butylated hydroxyltoluene are added to the soybean oilwith mixing. The lipid premix is then added to the main vessel withstirring. The composition is mixed until homogenous.

Inventive Example 9 is an aerosol foam skin cleanser including a skincleansing composition (Inventive Example 8), a low pressure foamingagent, and a package.

Inventive Example 9 Skin Cleansing Composition (Example 8) 97.15%Foaming agent (about 25 wt % isobutane &  2.85% about 75 wt %isopentane) Packaging Bag on Valve Propellant-Compressed Air filled to apressure Yes of about 12-15 psi Foam Density (g/ml) 0.85

Inventive Example 9 is made by first premixing the structured surfactantcomposition with foaming agent in a closed system and then injecting themixture into a bag which is fastened to a valve through the standardcrimping process. Then, the valve with bag and mixture is crimped onto acan (either metal, plastic, or glass). Then, propellant is added intothe can, but outside of the bag to provide a positive pressuredifferential outside of the bag.

Inventive Example 10 is a skin cleansing composition which can beincluded as part of an aerosol foam skin cleanser.

Inventive Example 10 Branched sodium trideceth-2-sulfate ST2S  7.8%Cocamidopropyl betaine  2.3% Trideceth-3 Iconal TDA-3-EthoxylatedTridecyl  1.1% Alcohol Sodium Chloride  4.02% Guar, HydroxypropylTrimonium Chloride, N-  0.29% Hance CG-17 Acrylates/C10-30 AlkylAcrylates Cross Polymer 0.023% Xanthan gum  0.22% Soybean Oil  4.85%Glyceryl Monooleate  0.05% butylated hydroxyltoluene  0.1% Disodium EDTA 0.13% Sodium Benzoate  0.27% Preservative 0.033% Perfume  0.25% WaterQ.S pH (using citric acid to adjust) 5.7

Inventive Example 10 is a blended multiphase composition, wherein thebenefit phase (including soybean oil, butylated hydroxytoluene, andmonoglyceryl monooleate) is dispersed in a cleansing phase. Thiscomposition is made by adding water to a main mixing vessel. Sodiumchloride, xanthan gum, guar hydroxypropyltrimonium chloride, and sodiumtrideceth sulfate are added to the water with constant mixing. Whilethat is mixing, a polymer premix is prepared by combiningAcrylates/C10-30 Alkyl Acrylates into trideceth-3 with mixing. Once thepolymer premix is dispersed, the premix is added to the main mixingvessel. Cocamidopropyl betaine, EDTA, and sodium benzoate are thensequentially added to the main mixing vessel with mixing. The pH is thenadjusted to about 5.7 with the addition of a pH modifier (like citricacid). The preservative and perfume are then added with good mixing.

The benefit phase is prepared by first creating a lipid premix byheating soybean oil to about 50° C. in a separate vessel. Monoglycerylmonooleate and butylated hydroxyltoluene are added to the soybean oilwith mixing. The lipid premix is then added to the main vessel withstirring. The composition is mixed until homogenous.

Inventive Example 11 is an aerosol foam skin cleanser including a skincleansing composition (Inventive Example 10), a low pressure foamingagent, and a package.

Example 11 Skin Cleansing Composition (Example 10) 95% Foaming agent(n-butane)  5% Packaging Dip Tube

Inventive Example 11 is made by first premixing the skin cleansingcomposition with foaming agent in a closed system and then injecting themixture into a canister.

Combinations

-   -   A. A packaged aerosol foaming skin cleanser, comprising: i) a        multiphase skin cleansing composition, comprising a structured        surfactant phase and a benefit phase, wherein the structured        surfactant phase comprises a branched structured surfactant, and        the benefit phase comprises a hydrophobic benefit agent; wherein        the multiphase cleansing composition is shear thinning and has a        viscosity of about 8,000 cps to about 80,000 cps; ii) a low        pressure foaming agent; and iii) a package.    -   B. The packaged aerosol foaming skin cleanser of paragraph A,        wherein the low pressure foaming agent comprises n-butane, an        isobutane blend, isopentane, or a combination thereof.    -   C. The packaged aerosol foaming skin cleanser of any paragraphs        A-B, wherein the low pressure foaming agent is a combination of        isobutane and isopentane with about 25 weight percent of the        isobutane and about 75 weight percent of the isopentane.    -   D. The packaged aerosol foaming skin cleanser of any of        paragraphs A-C, wherein the package is a dip tube package.    -   E. The packaged aerosol foaming skin cleanser of any of        paragraphs A-C, wherein the package is a bag on valve package.    -   F. The packaged aerosol foaming skin cleanser of paragraph E,        wherein the bag on valve package comprises a collapsible bag        attached to a valve, wherein the multiphase skin cleansing        composition is within the collapsible bag.    -   G. The packaged aerosol foam skin cleanser of paragraph F,        wherein the bag on valve package further comprises an exterior        wall at least partially surrounding the collapsible bag and a        propellant between the exterior wall and the collapsible bag.    -   H. The packaged aerosol foam skin cleanser of paragraph G,        wherein the propellant comprises n-butane, an isobutane blend,        isopentane, compressed air, or a combination thereof.    -   I. The packaged aerosol foam skin cleanser of any of paragraphs        G-H, wherein the propellant is filled to a pressure of about 12        psi to about 15 psi.    -   J. The packaged aerosol foaming skin cleanser of any of        paragraphs A-I, wherein the multiphase skin cleansing        composition is free from non-surfactant structurants.    -   K. The packaged aerosol foaming skin cleanser of any of        paragraphs A-J, wherein the multiphase skin cleansing        composition is free from humectants.    -   L. The packaged aerosol foaming skin cleanser of any of        paragraphs A-K, wherein the skin cleansing composition comprises        from about 5% to about 30%, from about 7% to about 25%, or from        about 8% to about 20%, by weight of the skin cleansing        composition, of the branched structured surfactant.    -   M. The packaged aerosol foaming skin cleanser of any of        paragraphs A-L, wherein the branched structured surfactant        composition comprises sodium trideceth-2 sulfate.    -   N. The packaged aerosol foaming skin cleanser of any of        paragraphs A-M, wherein the skin cleansing composition comprises        from about 3% to about 20%, or from about 5% to about 15%, by        weight of the skin cleansing composition, of the hydrophobic        benefit agent.    -   O. The packaged aerosol foaming skin cleanser of any of        paragraphs A-N, wherein the hydrophobic benefit agent comprises        petrolatum, soy bean oil, sucrose polyester, monoglyceryl        monooleate, or a combination thereof.    -   P. The packaged aerosol foaming skin cleanser of any of        paragraphs A-0, wherein the packaged aerosol foaming skin        cleanser comprises from about 3% to about 15%, about 4% to about        12%, or about 4% to about 10%, by weight of the aerosol foaming        skin cleanser, of the low pressure foaming agent.    -   Q. The packaged aerosol foaming skin cleanser of any of        paragraphs A-P, wherein the skin cleansing composition further        comprises a non-ionic low HLB emulsifier.    -   R. The packaged aerosol foaming skin cleanser of paragraph Q,        wherein the low HLB emulsifier comprises glyceryl        monohydroxystearate, isosteareth-2, trideceth-3, hydroxystearic        acid, propylene glycol stearate, PEG-2 stearate, sorbitan        monostearate, glyceryl laurate, laureth-2, cocamide        monoethanolamine, lauramide monoethanolamine, or mixtures        thereof.    -   S. The packaged aerosol foaming skin cleanser of paragraph Q,        wherein the low HLB emulsifier comprises trideceth-3.

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm.”

Every document cited herein, including any cross referenced or relatedpatent or application and any patent application or patent to which thisapplication claims priority or benefit thereof, is hereby incorporatedherein by reference in its entirety unless expressly excluded orotherwise limited. The citation of any document is not an admission thatit is prior art with respect to any invention disclosed or claimedherein or that it alone, or in any combination with any other referenceor references, teaches, suggests or discloses any such invention.Further, to the extent that any meaning or definition of a term in thisdocument conflicts with any meaning or definition of the same term in adocument incorporated by reference, the meaning or definition assignedto that term in this document shall govern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. A method for cleansing skin and enhancingdeposition of a benefit agent onto the skin comprising: a. providing anaerosol foamer comprising a container body, a collapsible bag containedin the container body, a low-pressure propellant disposed between thecontainer body and the collapsible bag, the low-pressure propellantcomprising air at a pressure of 20 psi or less at 21° C., and a foamableskin cleanser disposed in the collapsible bag, the foamable skincleanser comprising: i. a multiphase skin cleansing compositioncomprising:
 1. a structured surfactant phase comprising a branchedstructured surfactant;
 2. a benefit phase comprising a hydrophobicbenefit agent; wherein the multiphase cleansing composition is shearthinning and has a viscosity of about 8,000 cps to about 80,000 cps; andii. a low pressure foaming agent; b. dispensing the foamable skincleansing composition as a foam; c. cleansing the skin with the foam anddelivering the hydrophobic benefit agent to the skin.
 2. The method ofclaim 1, wherein the low pressure foaming agent comprises n-butane, anisobutane blend, isopentane, or a combination thereof.
 3. The method ofclaim 1, wherein the branched structured surfactant compositioncomprises sodium trideceth-2 sulfate.
 4. The method of claim 1, whereinthe structured surfactant phase comprises a lamellar structure.
 5. Themethod of claim 1, wherein the skin cleansing composition comprises fromabout 5% to about 15%, by weight of the skin cleansing composition, ofthe hydrophobic benefit agent.
 6. The method of claim 5, wherein thehydrophobic benefit agent comprises petrolatum, soybean oil, sucrosepolyester, monoglyceryl monooleate, or a combination thereof.
 7. Themethod of claim 1, wherein the packaged aerosol foaming skin cleansercomprises from about 4% to about 10%, by weight of the packaged aerosolfoaming skin cleanser, of the low pressure foaming agent.
 8. The methodof claim 1, wherein the skin cleansing composition comprises from about7% to about 25%, by weight of the skin cleansing composition, of thebranched structured surfactant.
 9. The method of claim 1, wherein themultiphase skin cleansing composition is free from humectants.
 10. Themethod of claim 1, wherein the multiphase skin cleansing composition isfree from non-surfactant structurants.
 11. The method of claim 1,wherein the cleansing phase further comprises a non-ionic low HLBemulsifier having an HLB value of about 1.5 to about
 13. 12. The methodof claim 11, wherein the non-ionic low HLB emulsifier comprises glycerylmonohydroxystearate, isosteareth-2, trideceth-3, hydroxystearic acid,propylene glycol stearate, PEG-2 stearate, sorbitan monostearate,glyceryl laurate, laureth-2, cocamide monoethanolamine, lauramidemonoethanolamine, or mixtures thereof.
 13. The method of claim 12,wherein the non-ionic low HLB emulsifier comprises trideceth-3.
 14. Themethod of claim 1, wherein the aerosol foamer is configured as bag onvalve package and the collapsible bag is attached to a valve.